Fiber optic light source having a dual characteristic fan

Abstract

A fiber optic light source cooled by a tube-axial fan having a blocking device covering a portion of its outlet. The blocking device generates a relatively higher velocity stream of cooling air just downstream of the blocking device in the direction of the rotation of the fan blades, while maintaining the velocity of cooling air is produced across the remainder of the fan outlet relatively unchanged. The higher velocity cooling air is used to cool the fiber optic cable ends while the relatively lower velocity cooling air is used to cool the bulb and other components of the light source. The dual characteristics of the cooling air produced by the fan provides an efficient, low noise cooling source that facilitates higher levels of light input without the problem of melting of the fiber optic cable ends.

I claim as my invention:  
     
       1. A fiber optic lighting device comprising: 
       an enclosure;  
       a fiber optic cable having an end disposed within the enclosure;  
       a lamp disposed proximate the end of the fiber optic cable;  
       a fan assembly having an outlet for directing a flow of cooling air into the enclosure;  
       a blocking device disposed proximate the outlet of the fan assembly for blocking the flow of cooling air through a portion of the outlet of the fan assembly to separate the flow of cooling air into a higher velocity portion for cooling the cable end and a lower velocity portion.  
     
     
       2. The device of claim  1 , wherein the blocking device comprises a plate covering a portion of the outlet of the fan assembly. 
     
     
       3. The device of claim  1 , wherein the blocking device comprises a plate attached to the fan assembly. 
     
     
       4. The device of claim  1 , wherein the blocking device comprises a plate attached to the enclosure. 
     
     
       5. The device of claim  1 , wherein the blocking device blocks the flow of cooling air through no more than one quarter of the area of the outlet. 
     
     
       6. The device of claim  1 , wherein the blocking device blocks the flow of cooling air through at least one quarter of the area of the outlet. 
     
     
       7. The device of claim  1 , wherein the fan assembly comprises a tube-axial fan. 
     
     
       8. The device of claim  1 , wherein the lamp comprises a metal halide light bulb. 
     
     
       9. A cooling arrangement for a fiber optic light source having a lamp and a fiber optic cable end located proximate the lamp, the cooling arrangement comprising: 
       a fan assembly having an outlet disposed to provide a flow of cooling air for cooling the cable end and the lamp;  
       a blocking device disposed proximate the outlet of the fan assembly for blocking the flow of cooling air through a portion of the outlet of the fan assembly to separate the flow of cooling air into a higher velocity portion for cooling the cable end and a lower velocity portion.  
     
     
       10. The cooling arrangement of claim  9 , wherein the fan assembly comprises a tube-axial fan having a generally circular outlet end, and wherein the blocking device comprises a plate disposed over a portion of the outlet. 
     
     
       11. The cooling arrangement of claim  10 , wherein the plate covers no more than one-quarter of the area of the outlet. 
     
     
       12. The cooling arrangement of claim  10 , wherein the plate covers at least one-quarter of the area of the outlet. 
     
     
       13. The cooling arrangement of claim  9 , wherein the blocking device is sized to provide an average velocity in the higher velocity portion that is at least 25% higher than the average velocity in the lower velocity portion. 
     
     
       14. The cooling arrangement of claim  9 , wherein the blocking device is sized to provide a velocity in the higher velocity portion that is at least 40% higher than the velocity in the lower velocity portion. 
     
     
       15. A fiber optic lighting device comprising: 
       an enclosure;  
       a fiber optic cable having an end disposed within the enclosure;  
       a lamp disposed proximate the cable end;  
       a tube axial fan assembly having an outlet for directing cooling air into the enclosure, the cooling air exiting the outlet having an average velocity across the outlet;  
       the outlet further comprising a first portion having an obstruction preventing the flow of cooling air therethrough and a second portion located immediately downstream of the first portion in the direction of rotation of the blades of the fan assembly, the velocity of the cooling air exiting the second portion having a velocity that is higher than the average velocity.  
     
     
       16. The device of claim  15 , wherein the fan assembly is located so that the cooling air exiting the second portion is directed to cool the end of the fiber optic cable. 
     
     
       17. The device of claim  15 , wherein the obstruction comprises a plate covering the first portion of the outlet. 
     
     
       18. The device of claim  17 , wherein the plate covers one quadrant of the outlet. 
     
     
       19. The device of ckaim  15 , wherein the obstruction is sized to provide a velocity of the cooling air exiting the second portion that is at least 25% higher than the average velocity. 
     
     
       20. The device of ckaim  15 , wherein the obstruction is sized to provide a velocity of the cooling air exiting the second portion that is at least 40% higher than the average velocity.